What’s happening: NASA astronauts Robert Behnken and Douglas Hurley returned home from the International Space Station aboard their SpaceX Crew Dragon capsule.
The Crew Dragon made a splashdown landing in the Gulf of Mexico just after 2:45 pm ET.
Why it’s important: This was the final stretch of a historic mission — and in some respects it was the most dangerous leg of the journey.
Our coverage of the SpaceX Crew Dragon landing has ended. Please check CNN Business for more news.
After a brief hangup caused by wayward fumes given off by propellant, the Crew Dragon opened its hatch and Behnken and Hurley took their first steps into Earth’s gravity after spending two months in the zero-G environment of space.
Behnken waved to the cameras before heading to his medical check up. Hurley followed shortly after and flashed a thumb’s up.
The astronauts are now on board SpaceX’s GO Navigator recovery vessel and will soon take a helicopter flight back to terra firma.
“Thanks for doing the most difficult part and the most important part,” Hurley said to mission control shortly before departing.
Spending two months in microgravity, then enduring a jarring trip home, can make readjusting difficult.
NASA astronaut Garret Reisman, who helped SpaceX develop Crew Dragon, said it took him about 15 minutes to sit up and another 15 to be able to stand after he returned to Earth after Space Shuttle missions.
The Crew Dragon recovery team has detected small amounts of NTO, or nitrogen tetroxide, a potentially toxic propellant used in the capsule’s onboard rocket engines.
The levels aren’t high enough to be dangerous to humans, according to SpaceX and NASA officials. And the air inside the spacecraft is clean.
But the safety teams want to put the issue to bed before the astronauts are allowed to disembark.
The recovery ship GO Navigator has closed in on the Crew Dragon spacecraft, with astronauts Doug Hurley and Robert Behnken still strapped inside.
At the ship’s rear is a large rig that has plucked the spacecraft out of the ocean and nestled it in an onboard dock, nicknamed the Dragon’s nest.
Soon after it’s on board, Behnken and Hurley will disembark and take their first steps back onto their home planet.
Two small boats swooped in immediately after splashdown. One is checking to make sure there are no toxic fumes around the Crew Dragon capsule. The other is working to drag the spacecraft’s parachutes out of the ocean.
Waiting in the wings is GO Navigator, a much larger vessel with a rig that can haul the Crew Dragon spacecraft itself out of the ocean.
Hurley and Behnken will disembark after their vehicle is safely on board. That’s expected to happen in less than an hour.
The first words from mission control to the astronauts were a humorous welcome home: “Thank you for flying SpaceX.”
The astronauts had a cheerful message for their flight doctors waiting to check them out as well:
“Let them know we’re feeling good.”
The Crew Dragon capsule has splashed down into the Gulf of Mexico, finishing off the hardest part of today’s journey.
And SpaceX personnel cheered loudly from inside mission control at SpaceX’s Hawthorne, California headquarters. The GO Navigator rescue ship will move in to haul the Crew Dragon spacecraft out of the water and allow Behnken and Hurley to disembark.
The first set of parachutes, called “drogue parachutes,” just stretched up above the Crew Dragon spacecraft. In about a minute, a second plume of four main parachutes — which are much larger — will fan out to continue slowing Hurley and Behnken’s descent.
They were followed quickly by the Crew Dragon’s four main parachutes. Behnken and Hurley are rapidly approaching their splashdown site. The parachutes will aim to slow the spacecraft down to 15 or 16 miles per hour before hitting the ocean.
As expected, mission control has lost communications contact with the Crew Dragon capsule. This is common for spacecraft going through the extreme conditions of reentry, when the dramatic heat and buildup of plasma briefly interfere with radio waves used for communication.
The blackout is expected to last six minutes.
Despite a tropical storm hammering Florida’s east coast, the Crew Dragon vehicle’s splashdown target off the panhandle has calm waters and low winds.
The astronauts’ capsule is beginning its final descent.
NASA spokesperson Dan Huot said it’s about 174 miles high and traveling less than 17,000 miles per hour. The Crew Dragon began its journey at the International Space Station, which orbits at about 250 miles above the Earth.
Crew Dragon had to take a long, looping journey back down because it’s traveling at such high speeds. But now that the capsule is getting back into the atmosphere, it’s expected to quickly decelerate.
SpaceX CEO Elon Musk is front and center at SpaceX’s mission control in Hawthorne, California. Sitting to his left is Gwynne Shotwell, the company’s president, chief operating officer and one of the company’s first employees.
The nose cone on the top of the Crew Dragon spacecraft is now sealed shut. The small, white cap is designed to protect the hardware that allows the vehicle to dock with the International Space Station, and it can swing open and shut on its hinge.
SpaceX wants to keep it shut for splashdown to keep all the docking components sealed off, as the company plans to reuse this Crew Dragon spacecraft on future missions.
And the more components stay dry, the better.
The most dangerous part of the astronauts’ return is underway.
Hurley and Behnken’s Crew Dragon spacecraft is plunging back toward the Earth’s thick atmosphere.
It’ll slow from 17,500 miles per hour to roughly 350 miles per hour before deploying parachutes. And it’s a rough ride for the astronauts, as they’ll experience G-forces up to five times stronger than Earth’s gravity.
Hurley and Behnken’s Crew Dragon spacecraft just lit up its engines, orienting the vehicle as it beelines for Earth.
There’s no going back now.
The spacecraft is traveling about 17,000 miles per hour, and Crew Dragon’s exterior will heat up to about 3,500 degrees Fahrenheit as it cuts through the atmosphere.
Inside the spacecraft cabin, the temperature should stay below 85 degrees Fahrenheit.
A thick heat shield will protect Behnken and Hurley, but the extreme heat and plasma buildup will cause a six-minute communications blackout, according to NASA.
A large circular trunk attached to the bottom of Hurley and Behnken’s spacecraft just popped off the capsule. This is intentional — the trunk contains the solar panels and power systems that Crew Dragon needs as its flying through space. But it’s not needed for the splashdown.
Letting go of the trunk also exposes the Crew Dragon’s heat shield on the bottom of the spacecraft, which will protect Hurley and Behnken from the intense the spacecraft is about to face as it reenters the atmosphere.
It’s a fairly quick trip from deorbit to the ground. Splashdown is still slated for 2:48 pm ET.
The Crew Dragon will ignite its thruster engines as it slices back into the thickest part of Earth’s atmosphere while traveling at 17,500 miles per hour. Rapid air compression and air friction will heat the outside of the spacecraft to about 3,500 degrees Fahrenheit — a dangerous part of the journey. But a heat shield on Crew Dragon’s exterior will keep Behnken and Hurley safe inside.
Behnken previously described his experience reentering the atmosphere aboard the Space Shuttle:
In some ways, however, the ride home on Crew Dragon will be much different from what the astronauts experienced during their prior Space Shuttle missions. The G-forces will be much more intense but won’t last quite as long.
As the Crew Dragon approaches Earth, it’ll deploy a set of parachutes, called “drogue parachutes,” to begin slowing its descent before a large plume of four parachutes fans out to slow the vehicle down even further. If all goes well, Crew Dragon will be traveling less than 20 miles per hour when it hits the water.
Reisman said that after getting used to the microgravity environment in space then experiencing the intense G-forces of the return flight, it takes awhile to readjust, he told CNN Business.
Weather officials are still keeping an eye on the winds and waves near the Crew Dragon’s splashdown zone.
But so far, it’s looking good.
SpaceX took a moment to show off the heat shield, attached to the bottom of the spacecraft, that will keep Behnken and Hurley safe while the vehicle plunges back into the atmosphere.
The heat shield is made out of a high-tech material called PICA, which was developed by NASA in the 1990s. And SpaceX worked with the space agency to develop its own variant.
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Rough winds and high waves are exactly what SpaceX and NASA are hoping to avoid.
But Tropical Storm Isaias is barreling toward Florida’s east coast on Sunday, threatening intense winds capable of damaging roofs and buildings.
NASA and SpaceX predetermined seven potential splashdown sites for this mission, four of which are to the west of Florida in the Gulf of Mexico: Pensacola, Tampa, Tallahassee, and Panama City. And in that area, the wind and wave heights appear calm enough for the Crew Dragon to land safely.
Still, weather officials are keeping a close eye on the forecast, and they could call off the splashdown any time before the spacecraft begins reentering the Earth’s atmosphere.
But calling off the splashdown is a situation NASA and SpaceX really hope to avoid.
The Crew Dragon will have to remain in orbit and circle back for another splashdown attempt in the next 24 to 48 hours, but if conditions still remain unfavorable, the spacecraft will likely have to make an emergency splashdown in some other area.
Behnken and Hurley have only about three days worth of the life-saving chemical (Lithium Hydroxide) needed to scrub the carbon dioxide out of the air on their spacecraft.
